"The coolest thing happened the other night: I go back into the bathroom to do my vocal warm ups and I go on Twitter to get excited. It's our 85th show, but everybody else's first time seeing it and it gets me motivated and ready."

"Then I read about this kid, Calvin, who had just beaten cancer, had Down syndrome, who was there; my album had got him through his treatment. And his mom wrote this letter to me and I read it, so at the beginning of 'So What' I know that I'm going straight out to the back."

She added that armed with the knowledge he was in attendance, she made a beeline for him during that segment of the show: "I flew out [on a trapeze] and said, 'I'm coming for you Calvin!' And I just happened to stop right over the wheelchair section and the mom just started sobbing. I started crying, he was excited; it will go down in history as one of the most amazing moments in my life."